The present invention relates to diode devices, in particular, to diode devices in which the separation of the electrodes and the angle between the electrodes is set and controlled using piezo-electric, positioning elements. These include thermionic converters and generators, photoelectric converters and generators, and vacuum diode heat pumps. It is also related to thermotunnel converters.
The use of individual actuating devices to set and control the separation of the electrodes using piezo-electric, electrostrictive or magnetostrictive actuators in a gap diode is disclosed in WO99/13562. This avoids problems associated with electrode spacing changing or distorting as a result of heat stress.
The use of composite materials as matching electrode pair precursors is disclosed in U.S. patent application Ser. No. 10/234,498. The approach comprises the steps of fabricating a first electrode with a substantially flat surface; placing over the first electrode a second material that comprises a material that is suitable for use as a second electrode, and separating the composite so formed along the boundary of the two layers into two matched electrodes.
In U.S. Pat. No. 4,880,975, Nishioka et al. disclose a fine adjustment mechanism for a scanning tunneling microscope that includes a cylindrical piezoelectric element fixed to a mounting member at one end and having an electrode each of the inner and outer walls. It is to be noted that the piezoelectric element does not form a housing for this device.
In “Close-Spaced Thermionic Converters with Active Spacing Control and Heat-Pipe Isothermal Emitters” (IEEE, 1996, pp 920-927), Fitzpatrick et al. teach a diode device having a first electrode attached to one end of three piezoelectric translators and a second electrode attached to the opposing end of the three piezoelectric translators. The lengths of the piezoelectric translators are modified by a signal from controlling circuitry so that the magnitude of a distance separating the electrodes is adjusted. It is to be noted that the piezoelectric translators are disposed inside a housing for the device.
In U.S. Pat. No. 6,232,546, DiMatteo teaches a diode device with the gap between electrodes controlled by piezoelectric actuators. It is to be noted that the piezoelectric actuators for ‘coarse’ control are mounted outside a housing for the device.
Definitions:
“Power Chip” is hereby defined as a device which uses a thermal gradient of any kind to create an electrical power or energy output. Power Chips may accomplish this using thermionics, thermotunneling, or other methods as described in this application.
“Cool Chip” is hereby defined as a device which uses electrical power or energy to pump heat, thereby creating, maintaining, or degrading a thermal gradient. Cool Chips may accomplish this using thermionics, thermotunneling, or other methods as described in this application.
“Gap Diode” is defined as any diode which employs a gap between the anode and the cathode, or the collector and emitter, and which causes or allows electrons to be transported between the two electrodes, across or through the gap. The gap may or may not have a vacuum between the two electrodes, though Gap Diodes specifically exclude bulk liquids or bulk solids in between the anode and cathode. The Gap Diode may be used for Power Chips or Cool Chips, for devices that are capable of operating as both Power Chips and Cool Chips, or for other diode applications.
When surface features of two facing surfaces of electrodes are described as “matching,” it means that where one surface has an indentation, the other surface has a protrusion and vice versa. Thus when “matched,” the two surfaces are substantially equidistant from each other throughout their operating range.